I agree with Dan, you're doing this the hard way! The fact that you have a spare now, just send it back to Lionel and get it fixed! I don't open them for that reason, I only fix stuff that someone else isn't willing to fix for me for free!
Thanks DanR and GRJ,
Again you both show that you are wise beyond your years. The reason I purchased this new one is I got so frustrated trying to connect with Lionel over the past couple of months especially after receiving such prompt service on the original return, that I saw as my only alternative was to purchase a new unit.